Just examples off the top of my head, wouldn’t take it too personally 
WB in full zones is laggy as hell for everyone, and those with old PCs that aren’t good enough to keep up with 100 odd people just lock up and have to stand there and wait for the boss to die (happened to me when I left full particles on to). If your PC does that in a raid I’d be shockedm and you really can’t contribute, but even my old potato laptop from 2004 could handle raiding, sieges were a bit of much for it though.